The Sharp Compet 20 (Model CS-20A) was Sharp's first electronic
calculator based on Silicon transistors, and Sharp's second
electronic calculator. Sharp's first machine, the
Sharp Compet 10, was
based on Germaniun transistors. Silicon transistors offered higher
speeds, lower power dissipation, and siginificantly improved
reliability.

The Compet 20 provides a capacity of fourteen digits, with true credit
balance (negative number) handling capability. It is a four-function
machine, with automatic floating and fixed decimal point modes. The
original sales price for the machine was around $1,050 in the US
at introduction in the fall of 1965.

To learn more about the Compet 20, see the Old Calculator Web Museum
exhibit: Sharp Compet 20.